Science, as a concept, is relatively new. Benjamin Franklin wasn’t a scientist probing the mysteries of amber and wool and electricity and ‘air baths’; he was a natural philosopher. Antonie van Leeuwenhoek was simply a man with a proclivity towards creating new and novel instruments. Robert Hooke was a naturalist and polymath, and Newton was simply a ‘man of science’. None of these men were ever called ‘scientists’ in their time; the term hadn’t even been coined yet.
The word ‘scientist’ wouldn’t come into vogue until the 1830s. The word itself was created by William Whewell, reviewing The Connexion of the Physical Sciences by Mary Somerville. The term used at the time, ‘a man of science’, didn’t apply to Mrs. Somerville, and, truth be told, the men of science of the day each filled a particular niche; Faraday was interested in electricity, Darwin was a naturalist. Mary Somerville was a woman and an interdisciplinarian, and the word ‘scientist’ was created for her.